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Steacyite
Steacyite is a complex silicate mineral containing thorium and uranium; formula . It forms small brown or yellow green crystals, often cruciform twinned crystals. It is radioactive. It was discovered at Mont-Saint-Hilaire, Quebec in 1982 and is named after Harold Robert Steacy (1923–2012), mineralogist. References Notes Sources Handbook of Mineralogy See also *List of minerals *List of minerals named after people This is a list of minerals named after people. The chemical composition of the mineral follows the name. A * Abelsonite: – American physicist Philip Hauge Abelson (1913–2004) * Abswurmbachite: – German mineralogist Irmgard Abs-Wurmbac ... Calcium minerals Thorium minerals Uranium minerals Cyclosilicates Tetragonal minerals Minerals in space group 124 {{silicate-mineral-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Minerals Named After People
This is a list of minerals named after people. The chemical composition of the mineral follows the name. A * Abelsonite: – American physicist Philip Hauge Abelson (1913–2004) * Abswurmbachite: – German mineralogist Irmgard Abs-Wurmbach (1938–2020) *Adamite: – French mineralogist Gilbert Joseph Adam (1795–1881) * Agrellite: – English optical mineralogist Stuart Olof Agrell (1913–1996) * Agricolaite: – German scholar Georgius Agricola (1494–1555) * Aheylite: – American geologist Allen V. Heyl (1918–2008) * Albrechtschraufite: – Albrecht Schrauf (1837–1897), professor of mineralogy, University of Vienna * Alexandrite: Variety of chrysoberyl (): – Russian monarch, Tsar Alexander II of Russia (1818–1881) * Alforsite: – American geologist John T. Alfors (1930–2005) * Allabogdanite: – Alla Bogdanova (1947 - 2004), Geological Institute, Kola Science Centre of Russian Academy of Sciences * Allanite series: sorosilicate – Scottish m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Minerals
This is a list of minerals which have Wikipedia articles. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various ''species''. Within a mineral species there may be variation in physical properties or minor amounts of impurities that are recognized by mineralogists or wider society as a mineral ''variety''. Mineral variety names are listed after the valid minerals for each letter. For a more complete listing of all mineral names, see List of minerals recognized by the International Mineralogical Association. A :Varieties that are not valid species: *Adamantine spar (variety of corundum) *Agate (variety of chalcedony and quartz) *Alabaster (variety of gypsum) *Alexandrite (variety of chrysoberyl) *Allingite (synonym of amber) *Alum *Amazonite (variety of microcline) *Amethyst (purple variety of quartz) *Ametrine (variety of quartz) *Ammolite (organic; also a gemstone) *Amos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetragonal
In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the Cube (geometry), cube becomes a rectangular Prism (geometry), prism with a square base (''a'' by ''a'') and height (''c'', which is different from ''a''). Bravais lattices There are two tetragonal Bravais lattices: the primitive tetragonal and the body-centered tetragonal. The body-centered tetragonal lattice is equivalent to the primitive tetragonal lattice with a smaller unit cell, while the face-centered tetragonal lattice is equivalent to the body-centered tetragonal lattice with a smaller unit cell. Crystal classes The point groups that fall under this crystal system are listed below, followed by their representations in international notation, Schoenflies notation, orbifold notation, Coxeter notation and mineral examples.Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Twinning
Crystal twinning occurs when two or more adjacent crystals of the same mineral are oriented so that they share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals that are tightly bonded to each other. The surface along which the lattice points are shared in twinned crystals is called a composition surface or twin plane. Crystallographers classify twinned crystals by a number of twin laws, which are specific to the crystal structure. The type of twinning can be a diagnostic tool in mineral identification. There are three main types of twinning. The first is growth twinning which can occur both in very large and very small particles. The second is transformation twinning, where there is a change in the crystal structure. The third is deformation twinning, in which twinning develops in a crystal in response to a shear stress, and is an important mechanism for permanent shape changes in a crystal. Definition T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclosilicates
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, the crystalline forms of silica (silicon dioxide, ) are usually considered to be tectosilicates, and they are classified as such in the Dana system (75.1). However, the Nickel-Strunz system classifies them as oxide minerals (4.DA). Silica is found in nature as the mineral quartz, and its polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium Minerals
Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium radioactive decay, radioactively decays, usually by emitting an alpha particle. The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes of uranium, isotopes, making them useful for dating the age of the Earth. The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99% of uranium on Earth) and uranium-235 (which has 143 neutrons). Uranium has the highest atomic weight of the primordial nuclide, primordially occurring elements. Its density is about 70% higher than that of lead and slightly lower than that of gold or tungsten. It occurs naturally in low concentrations of a few Parts-per notation#Parts-per expressions, parts per million in soil, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thorium Minerals
Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided. All known thorium isotopes are unstable. The most stable isotope, 232Th, has a half-life of 14.05 billion years, or about the age of the universe; it decays very slowly via alpha decay, starting a decay chain named the thorium series that ends at stable 208 Pb. On Earth, thorium and uranium are the only elements with no stable or nearly-stable isotopes that still occur naturally in large quantities as primordial elements. Thorium is estimated to be over three times as abundant as uranium in the Earth's crust, and is chiefly refined from monazite sands as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Minerals
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossils of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name comes from Latin ''calx'' " lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and pharmaceuticals for calci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harold Robert Steacy
Harold "Hal" Robert Steacy (June 7, 1923 – April 7, 2012) was a Canadian mineralogist who was the curator of the Canadian National Mineral Collection at the Geological Survey of Canada in Ottawa. The mineral steacyite Steacyite is a complex silicate mineral containing thorium and uranium; formula . It forms small brown or yellow green crystals, often cruciform twinned crystals. It is radioactive. It was discovered at Mont-Saint-Hilaire, Quebec in 1982 and is ... is named for him.Dunn et al., 1983, p. 473 References Literature cited *Dunn, P.J., Fleischer, M., Burns, R.G. and Pabst, A. 1983New mineral names.American Mineralogist 68:471–475. Canadian mineralogists Canadian curators Geological Survey of Canada personnel 1923 births 2012 deaths {{geologist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mont-Saint-Hilaire, Quebec
Mont-Saint-Hilaire () is a suburb of Montreal on the South Shore (Montreal), South Shore of southeastern Quebec, Canada, on the Richelieu River in the La Vallée-du-Richelieu Regional County Municipality, Regional County Municipality of La Vallée-du-Richelieu. The population as of the Canada 2021 Census was 18,859. The city is named after the Mont Saint-Hilaire. A significant deposit of the semi-precious mineral sodalite is located near Mont-Saint-Hilaire. History Jean-Baptiste Hertel de Rouville was granted the seignory of the region in 1694. By 1745 a mountain village had been formed with the first chapel being built in 1798 near the Richelieu River. Nearly twenty years later, in 1822, a ferry operating between Beloeil and Mont-Saint-Hilaire came into service. A bridge, enabling Beloeil and St. Hilaire to be connected by rail, was built in 1848 by the St. Lawrence and Atlantic Railway. The Campbell family, which owned the mountain after the Rouvilles, sold the mountain t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered ''radioactive''. Three of the most common types of decay are Alpha decay, alpha, Beta decay, beta, and Gamma ray, gamma decay. The weak force is the Fundamental interactions, mechanism that is responsible for beta decay, while the other two are governed by the electromagnetic force, electromagnetic and nuclear forces. Radioactive decay is a randomness, random process at the level of single atoms. According to quantum mechanics, quantum theory, it is impossible to predict when a particular atom will decay, regardless of how long the atom has existed. However, for a significant number of identical atoms, the overall decay rate can be expressed as a decay constant or as a half-life. The half-lives of radioactive atoms have a huge range: f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. The word ''crystal'' derives from the Ancient Greek word (), meaning both "ice" and " rock crystal", from (), "icy cold, frost". Examples of large crystals include snowflakes, diamonds, and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Polycrystals include most metals, rocks, ceramics, and ice. A third cat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
